4.5 billion B.C.Planet Earth formed.3 billion B.C.First signs of primeval life (bacteria and blue-green algae) appear in oceans.600 million B.C.Earliest date to which fossils can be traced.4.4 million B.C.Earliest known hominid fossils (Ardipithecus ramidus) found in Aramis, Ethiopia, 1994.4.2 million B.C.Australopithecus anamensis found in Lake Turkana, Kenya, 1995.3.2 million B.C.Australopithecus afarenis (nicknamed “Lucy”) found in Ethiopia, 1974.2.5 million B.C.Homo habilis (“Skillful Man”). First brain expansion; is believed to have used stone tools.1.8 million B.C.Homo erectus (“Upright Man”). Brain size twice that of Australopithecine species.1.7 million B.C.Homo erectus leaves Africa.100,000 B.C.First modern Homo sapiens in South Africa.70,000 B.C.Neanderthal man (use of fire and advanced tools).35,000 B.C.Neanderthal man replaced by later groups of Homo sapiens (i.e., Cro-Magnon man, etc.).18,000 B.C.Cro-Magnons replaced by later cultures.15,000 B.C.Migrations across Bering Straits into the Americas.10,000 B.C.Semi-permanent agricultural settlements in Old World.10,000–4,000 B.C.Development of settlements into cities and development of skills such as the wheel, pottery, and improved methods of cultivation in Mesopotamia and elsewhere.5500–3000 B.C.Predynastic Egyptian cultures develop (5500–3100 B.C.); begin using agriculture (c. 5000 B.C.). Earliest known civilization arises in Sumer (4500–4000 B.C.). Earliest recorded date in Egyptian calendar (4241 B.C.). First year of Jewish calendar (3760 B.C.). First phonetic writing appears (c. 3500 B.C.). Sumerians develop a city-state civilization (c. 3000 B.C.). Copper used by Egyptians and Sumerians. Western Europe is neolithic, without metals or written records.3000–2000 B.C.Pharaonic rule begins in Egypt. King Khufu (Cheops), 4th dynasty (2700–2675 B.C.), completes construction of the Great Pyramid at Giza (c. 2680 B.C.). The Great Sphinx of Giza (c. 2540 B.C.) is built by King Khafre. Earliest Egyptian mummies. Papyrus. Phoenician settlements on coast of what is now Syria and Lebanon. Semitic tribes settle in Assyria. Sargon, first Akkadian king, builds Mesopotamian empire. The Gilgamesh epic(c. 3000 B.C.). Systematic astronomy in Egypt, Babylon, India, China.3000–1500 B.C.The most ancient civilization on the Indian subcontinent, the sophisticated and extensive Indus Valley civilization, flourishes in what is today Pakistan. In Britain, Athenian democracy develops. Aeschylus, Greek dramatist (525–465 B.C.). Pythagoras, Greek philosopher and mathematician (582?–507? B.C.). Confucius (551–479 B.C.)develops ethical and social philosophy in China. The Analects or Lun-yü (“collected sayings”) are compiled by the second generation of Confucian disciples. Buddha (563?–483? B.C.) founds Buddhism in India.500–400 B.C.Greeks defeat Persians: battles of Marathon (490 B.C.), Thermopylae (480 B.C.), Salamis (480 B.C.). Peloponnesian Wars between Athens and Sparta (431–404 B.C.)—Sparta victorious. Pericles comes to power in Athens (462 B.C.). Flowering of Greek culture during the Age of Pericles (450–400 B.C.). The Parthenon is built in Athens as a temple of the goddess Athena (447–432 B.C.). Ictinus and Callicrates are the architects and Phidias is responsible for the sculpture. Sophocles, Greek dramatist (496?–406 B.C.). Hippocrates, Greek “Father of Medicine” (born 460 B.C.). Xerxes I, king of Persia (rules 485–465 B.C.).400–300 B.C.Pentateuch—first five books of the Old Testament evolve in final form. Philip of Macedon, who believed himself to be a descendant of the Greek people, assassinated (336 B.C.) after subduing the Greek city-states; succeeded by son, Alexander the Great (356–323 B.C.), who destroys Thebes (335 B.C.), conquers Tyre and Jerusalem (332 B.C.), occupies